Despite the advancements in the fields of microfluidics, microfabrication and the like, there remains a fundamental problem with the implementation of these technologies in achieving their full potential. Specifically, although microfluidic systems are readily applicable to high throughput, low volume, automatable chemical and biochemical analyses and syntheses, many of the advantages gained through the use of microfluidic systems are lost through the lack of interfacing systems that are capable of functioning at the horizons of these microfluidic systems. For example, one of the major advantages of these microfluidic systems is the ability to perform operations using extremely small fluid volumes, thereby requiring smaller amounts of potentially valuable reagents and/or samples. However, although a microfluidic system may be capable of operating with fluid volumes in the nanoliter range, the lack of fluid handling systems capable of delivering such volumes to these microfluidic systems renders this advantage substantially unrealized. Specifically, the user is still required to utilize reagents and/or samples in the 1 to 10 .mu.l range.
One example of a fluidic interface which addresses these problems, namely, the introduction of samples and other fluids into microfluidic analytical systems, is described in commonly assigned U.S. application Ser. No. 08/671,986, filed Jun. 28, 1996, now U.S. Pat. No. 5,779,868 and incorporated herein by reference. In brief, the described system includes an electropipettor interfaced with the channels of a microfluidic device, for electrokinetically introducing very small volumes of samples or other materials into the microfluidic device.
In addition to fluidic interfaces, microfluidic systems also require additional device:world interfaces, including an interface between the device and the detection, sensing or monitoring means that are utilized with the system. Also required are interfaces between the device and the systems that control the operation of the device, such as systems that control fluid direction and transport within the device, and/or environmental conditions present within or around the device, and the like.
Microfluidic devices previously described in the literature have generally included only crude device:world interfaces which severely limited or eliminated a substantial proportion of the promised benefits of microfluidic systems, including automatability, ease of use, low volume and high throughput, which have been the goals of these systems.
Accordingly, there exists a need in the art for improved interfaces between microfluidic devices and the ancillary systems that are utilized with these microfluidic systems, such that these microfluidic systems can realize a greater proportion of their promised benefits. The present invention provides a solution to many of these and other problems.